Referring to FIG. 1, after drilling a water well 10, an electric pump 12, which is connected to a hose 14 and an electric power cord 16, must be installed in the well for pumping water through the hose 14 to the surface. The power cord typically includes four wires, three for supplying single phase 220-volt power and a fourth to apply a ground for the pump 12. The power cord is typically spot bound to the hose 14 or pipe (with binding locations 18 separated by twenty feet of hose length or less) with tape or clamps as the pump 12, hose 14 and cord 16 are being lowered into the well.
Unfortunately, this method leaves quite a bit to be desired. First, it requires the repeated action of binding the cord 16 to the hose 14, slowing the pump lowering and installation process. Second, the cord 16 is exposed both as it is being lowered and after the installation process is complete and the pump is in operation. It is a common practice in well drilling to sheath the interior of the upper part of the well hole with metal tube 20, to prevent the movement of mud into the well. Further down, where the well hole extends through bedrock 22, the tube 20 is unnecessary. The transition 24 from tube 20 to unsheathed rock can include some rather sharp rock surfaces or the hole may not be plumb. As a result, the power cord 16, which is clad only in standard insulation, may be severed by sharp rocks during pump installation or operation or when pulling the pump during servicing. In either instance the cord must be retrieved and repaired, which is a time consuming operation.
A number of references do address problems associated with operating electrical equipment in oil drilling and in association with vacuum cleaner hoses.
Doubleday, U.S. Pat. No. 3,961,647, discloses a suction pipe for a suction operated cleaner in which the pipe sections are provided with integral extensions thereon forming an axial channel along the outside of the pipe which is open on one side to receive a supply conduit, such as an electric cable. FIGS. 2, 3, and 4 are of particular relevance to the cable retainment. However, the suction pipe taught by Doubleday includes many interlocking pieces which would be susceptible to leakage over time and would not be suitable for an application that should not leak for an extended period of time, such as a well.
Neroni et al., U.S. Pat. No. 4,064,355, disclose a vacuum cleaner hose having a longitudinally attached conduit retaining an electric cord. The cord is not removable from the conduit, other than by pulling it out from one of the ends, and there is no teaching of using such a device for the installation of a pump in a water well.
Peterman, U.S. Pat. No. 4,569,392, discloses a flexible control line for communication in a well bore having a communication tube and a strength member extending along the tube. The tube and strength member are encapsulated in a sheath of elastomeric material. Peterman does not suggest that the communication tube includes an electrical wire for controlling a pump, nor its use for water wells.
Davis, U.S. Pat. No. 4,361,937, discloses a cable banding lock ring that engages around the strap between the cable and discharge pipe for use in a well. Johnson et al., U.S. Pat. No. 4,068,966 another mounting apparatus.
Escaron et al., U.S. Pat. No. 4,337,969, disclose a rigid extension member for use with a well-logging cable in a bore hole which has a structure for protecting the well-logging cable disposed along the length of, and on the outer surface of, a cylindrical tube. The extension member has a fixed length with screw threads on either end. Moreover, the wires are encased in a single insulating medium which does not appear to be easily separable.
Merry, U.S. Pat. No. 3,814,835; Evans et al., U.S. Pat. No. 3,844,345; and Plummer, U.S. Pat. No. 3,095,908 all disclose tubular members with associated control lines.
Opie et al, U.S. Pat. No. 4,869,238; Jones, U.S. Pat. No. 5,201,908; and Jones, U.S. Pat. No. 5,386,817 all show endoscope sheaths. Although these devices show a structure having a number of lumens or channels, the main lumen or channel is designed to allow the passage of an endoscope and the associated fiber optics, rather than the substantial amounts of water yielded by a water well pump. Moreover, electrical wires do not appear to be included. The auxiliary channels shown are for water, air and vacuum.
What is needed, therefore, but not yet available, is an apparatus and method for facilitating the installation of a water well pump into a well hole that obviates the need to repeatedly tie a power cord to the well pipe as the pump is being lowered into the well hole and which protects the power cord during and after the pump installation process.